This study aims to investigate the effects of learning environmental education on the knowledge, awareness, global warming decreasing behavior, and critical thinking of eighty grade 11 students from two classes. The Four Noble Truths method with metacognitive techniques and traditional teaching method were used for the investigation. The sample was obtained by using cluster random sampling techniques. The Four Noble Truths method with metacognitive techniques was used for forty students that made up the experimental group while the traditional learning method was used for the control group consisting of forty students. The research instruments included five- lesson plans using the Four Noble Truths method with three metacognitive techniques: intelligibility, plausibility and wide-applicability (each plan consists of three hours learning per week); a knowledge test on global warming; questionnaire on global warming awareness; questionnaire on global warming decreasing behavior; and a critical thinking test. The major findings revealed that the experimental group and based on prior Biology learning outcome had more knowledge, awareness, global warming decreasing behavior, and critical thinking prior to learning. The high Biology achievers had higher awareness of global warming in two areas, global warming decreasing behavior in one area and critical thinking than the lower Biology achievers in three areas. The experimental group had more knowledge, awareness of global warming generally and in one area, global warming decreasing behavior generally and in one area and overall critical thinking in three aspects than the control group students. In addition, there were statistical correlations between prior Biology learning outcome with learning model and global warming awareness, global warming decreasing behavior, and critical thinking.